This qualitative study examines the significance and effectiveness of participatory health training as a tool for peace building. It does so by analysing a case of training for 'health promoters' run by a Cambodian government health agency. The authors observed participants during the training and interviewed those involved in the courses. A developing capacity for coexistence and reconciliation between individuals who had been on opposite sides during the years of Khmer Rouge terror and continuous internal war was observed among both participants and trainers. Factors embodied in the training that facilitated favourable changes in self and in relations with others were identified as: (1) 'space for dialogue' was created by concrete common public health interests and urgent needs
(2) training took place 'live-in' style in a rural setting
(3) course contents and methods were consistent with peace education
(4) trainers had a conscious function as role models
and (5) there was continuity of effort and consequent accumulation of experience. To build peace, as well as conducting training directly on a technical topic, these essential factors need to be incorporated in the training programmes.